Intervalometer



Feb. 27, 1945. w. T. VAN HORN INTERVALOMETER Filed April 25, 1344 Patented Feb. 27, 1945 f 'UNITED" STATES PATENT OFFICE f l I 2,370,213

INTERVALOMETER William T. Van Horn, Oaklyn, N. J.

Application April 25, 1944, Serial No. 532,680

(Granted under the act of March a, 1883, as

amended April 30, 1928; 370 0. G. 757) 7 Claim.

This invention relates to devices which are manually or otherwise operable to actuate a series of mechanisms in a preselected order. Such devices are commonly called intervalometers. 7

One of the uses to which an intervalometer is put is that of releasing bombs or the like from aircraft. Several bombs are generally carried by an aircraft, some of the bombs overlying others, depending upon the arrangement of the bomb racks, bomb bay doors etc., and it is necessary that the doors be opened and the bombs be released in a particular order, so that a higher mounted bomb does not fall upon one which has not yet been released, or that a bomb is not released before the doors are open. Another factor entering into the proper sequence of release of the bombs is that many of the bombs carried are there is danger of them being operated inv improper order. Preoccupation of the pilot or operator with other simultaneous duties is a primary cause of such improper operation. By the use of an intervalometer it is assured that each operation will occur in its proper predetermined sequence, even though the elapsed time for an entire sequence to be completed may be only a few seconds. An intervalometer may be moved throughout its entire range in a single stroke or in any desired number of partial strokes. In

any event there is assurance that the release operations will occur in their proper predetermined sequence. Thus when the handle is moved through part of its range it will actuate the re- "leases which it passes during such movement.

'When it is moved further it will merely resume the actuationof the remaining releases in their proper order.

It is the purpose of my invention to provide an improved intervalometer which may be moved throughout its stroke in one continuous operation or in interrupted operations, there being re- ;leasable means operable to hold it at the end of anyinterrupted operation, and wherein theac- "tuating' means is positively moved towards its,

final position by the intervalometer handle during its movement, whereupon the actuating means is removed from the path and influence of the handle.

Other objects will become apparent as the description progresses in connection with the an- 'a plane perpendicular to that of Fig. l, and showing a sequence of events in the operation of one of the elements of the intervalometer; and

Fig. 7 is a partial sectional view, taken in the plane 1-1 of Fig. 4 and looking in the direction of the arrows.

As shown in Fig. 1, a flat circular plate I has three lightening holes therein, defining radialj spokes 2. A handle 3 having a knob 4 at its outer end is pivotally attached to the plate at its center by means of a bolt 5 or the like. Integral with the handle 3 is a lever arm 6 which lies parallel to but slightly spaced from the plane of the platev I as better shown in Figs. 4 to 6.

' A flange 1 is attached to the periphery of the plate I, extending at right angles thereto and for about three-quarters of the circumference. On its bottom portion it has a guide slot 8 in which the outer end of the lever arm 6 slides. .On its top portion a slot 9 provides both a guide and a stop ordetent means for the handle 3. As shown in Fig. 2 the slot 9 'is smooth on its outer side. On the side towards the plate I, the slot hasa series of spaced notches l0 which are of a length suflicient to permit the entrance of the handle 3. The handle 3 is slightly bowed and is so tensioned that it normally bears against the notched side of the slot [0. In order to move the handle around its pivot 5 it must be pushed away from the notches and heldagainst the smooth side of the slot 9' while its angular position with respect to the plate I is changed. The. handle can be moved from one to the other end of the slot 9 in one stroke by holding it against the smooth side of the slot. When it is desired to move it only from one notch to the next it is disengaged irom the notch, shifted, and allowed to fall into the next desired notch under its own tension. The distance between the notches is determined by the positions of devices engaged asvdeia are unafiected after said disengagement; and means attached to said latches for connecting them to devices arranged to be actuated thereby.

3. The device described in claim 2 wherein detent means are provided to stop the movement of said member after it has become disengaged from any of said dogs.

4. In an intervalometer; a plate having an elongated slot therein, said slot having a short end portion of greater width than the remainder; av latch comprising a portion mounted in said slot for sliding movement therein and having a dog pivotally attached to said portion, and elements on either side of said plate preventing the withdrawal of said dog from said slot except at the wider portion thereof; said pivotally attached dog being of such width as to pass only through the wide portion of said slot; and a movable member engageable with said dog to slide said latch along said slot until said dog passes through 20 the wide portion of said slot; said latch being adapted to be connected to a device which is actuated by the movement of the latch.

5. The device of claim 4 wherein said plate is,

circular and said movable member includes a handle extending beyond the periphery of said plate; and a flange on the periphery of said plate having a pair of guide slots through which said 

